Design and Fabrication of a Prism Sheet with Roll-to-roll Fabrication Process

• Main Authors: Chih-Chin Tzeng, 曾智勤
• Other Authors: Min-Wen Wang
• Format: Others
• Language: zh-TW
• Published: 2008
• Online Access: http://ndltd.ncl.edu.tw/handle/45115826777477215532

碩士 === 國立高雄應用科技大學 === 機械與精密工程研究所 === 96 === This study is devoting in developing roll-to-roll fabrication of brightness enhancement prism sheet for liquid crystal display application. The roll-to-roll fabrication process has the advantages in fast and mass replication of microstructures, and it is a good fit for fabricating devices based on flexible substrates. The prism sheet designed in this study is similar to 3M BEF, computer aided engineering was applied to analyze the optical distribution of the prism sheet using Trace Pro software. From the simulation results, we can find that with the same v-cut micro pattern design, the higher refractive index of the UV curable resin, the high the brightness enhance effect till the refractive index is higher than 2.0. The results also shown that when the resin has a refractive index higher than 1.8, the enhancement effect with one prism is better than that of two vertically aligned 3M BEF, thus one can use one such prism to replace the two 3M BEF. The designed prism sheet, with 50μm in width and 25μm in depth V-cut micro patterns, has been successfully fabricated using self developed roll-to-roll fabrication equipment. Replication rate of 99.5% has been achieved in the roll-to-roll replication process. Optical brightness enhancement effect has been measured for the fabricated sheet by assembling the sheet a 2.5” backlight module, results show that the enhancement of the brightness with one single prism is better than that without any prism sheet by 1.4~1.6 times, and that with two vertically aligned sheets is 2~2.2 times. This study demonstrates that prism sheet can be fabricated using roll-to-roll fabrication process, and the cost of the prism can be reduced with such a fast replication process.